As part of a continuing effort in finding more cost effective, environmentally friendly, and independent solutions to fuel production and consumption, the conversion of ethanol and other alcohols to hydrocarbons has become an active field of study. Ethanol is of primary interest as an alcohol feedstock because it has the potential to be made in large quantity by renewable means (e.g., fermentation of biomass). However, several hurdles need to be overcome before such a process can become industrially feasible for producing hydrocarbon blendstocks of substantial equivalence to gasoline and other petrochemical fuels.
A particular drawback in the use of ethanol in catalytic conversion is its tendency to produce a significant quantity of ethylene and other gaseous hydrocarbons. Gaseous hydrocarbons are generally an undesirable component in a hydrocarbon fuel. A hydrocarbon fuel is more preferably composed predominantly of liquid hydrocarbons, with the gaseous hydrocarbon fraction minimized to the extent possible.
Thus, there have been continued efforts in reducing the gaseous hydrocarbon fraction in alcohol conversion processes of the art. Some of these efforts rely on careful selection of the catalyst, careful selection of the alcohol, and/or careful selection of the conversion conditions, such as use of an elevated pressure during the process. However, the efforts thus far considered have the drawback of either requiring specialized conditions that are costly or would be a challenge to adopt on a commercial scale, or they are generally not widely applicable to a range of catalysts and alcohols. A process that is more amenable to commercial scale-up and more widely applicable to a range of catalysts, alcohol-containing starting materials, and process conditions would be a significant advance in the catalytic conversion of alcohols to hydrocarbons.